Remove hitscan Add projectiles Make the maps brighter and with more detail Make more tactical jumps in the maps Allow for more realistic and diverse textures Make the campaign storyline more cinematic and less star treky More missions on earth Remove the flailing animation from elites Make the game take skill Lower the bullet magnetism Add the ability to customize the controls Remove all the bad maps like Lockout, Terminal, Turf, pretty much just remove all of them except the Halo CE remakes and have a dedicated team design maps for competitive play instead of randomly throwing around -blam!- Lastly, make halo 2 not suck